All known sail riggings present a problem of roll stability, the wind generated forces on the sail generating a capsizing moment as well as the propulsion force. In order to provide stability, ballast may be provided, or on outrigger may be employed. While these arrangements serve to increase the roll stability, they have the detrimental effect of increasing drag and, accordingly, limiting the speed of the vessel. Among the prior art solutions to the problem of roll stability are the sail riggings shown in U.S. Pat. No. 4,068,607, Harmon: German Pat. No. 1,119,702, Pohl; and European Patent Application No. 0 020 121, Williams.
It is the primary object of the present invention to provide a sail rigging which substantially eliminates the capsizing moment without imposing undesirable drag.
It is a further object of the invention to provide a sail rigging which is easily controlled by the operator.
Another object of the invention is the provision of a sail rigging which permits control of the direction of motion of the vessel without the need for a rudder.